Android Assign Array Values To Buttons

Question

I am making a quiz game similar to the logo quizzes and im trying to create the input style on which they apps have. They have random mixed up letters and the user has to find the letter which make up the correct answer. So far i have an array list that hold the buttons and the correct answers letters, then i loop through the array lists and assign the buttons text to the letters from the correct answers array list but causing a force stop with no errors. Anyone know why?

ArrayList<Character> answer = new ArrayList<Character>();
ArrayList<Button> buttons = new ArrayList<Button>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Button btn1 = (Button) findViewById(R.id.button1);
    Button btn2 = (Button) findViewById(R.id.button2);
    Button btn3 = (Button) findViewById(R.id.button3);
    Button btn4 = (Button) findViewById(R.id.button4);
    Button btn5 = (Button) findViewById(R.id.button5);
    Button btn6 = (Button) findViewById(R.id.button6);
    Button btn7 = (Button) findViewById(R.id.button7);
    Button btn8 = (Button) findViewById(R.id.button8);
    Button btn9 = (Button) findViewById(R.id.button9);
    buttons.add(btn1);
    buttons.add(btn2);
    buttons.add(btn3);
    buttons.add(btn4);
    buttons.add(btn5);
    buttons.add(btn6);
    buttons.add(btn7);
    buttons.add(btn8);
    buttons.add(btn9);

    String testAnswer = "Answer";
    //convert to chars and add to arraylist for shuffling
    for(char a : testAnswer.toCharArray()){
        answer.add(a);
    }
    Collections.shuffle(answer);


    //loop over buttons and letters and assign each button with a letter
    for(char a : answer){
        for(Button bb : buttons){
            bb.setText(String.valueOf(a));
        }
    }

}

Why do you want to set every button's text to only the last answer? (That's what your double for is doing.) — Jashaszun
– Jashaszun, Commented Aug 1, 2014 at 16:05
Yeah it is, what i want is to set each character from the answer array to an available button from the buttons array — user3439600
– user3439600, Commented Aug 1, 2014 at 16:07
Instead of your for (char a : testAnswer.toCharArray()) { answer.add(a); } you should write answer = new ArrayList<Character>(Arrays.asList(testAnswer.toCharArray()));. — Jashaszun
– Jashaszun, Commented Aug 1, 2014 at 16:07
But that wants me to change the String testAnswer to an ArrayList<Character> — user3439600
– user3439600, Commented Aug 1, 2014 at 16:12

i_turo · Accepted Answer · 2014-08-01 17:02:31Z

1

I can't see why the app force stops from the code you have given (it seems fine), but I discovered another problem:

//loop over buttons and letters and assign each button with a letter
for(char a : answer){
    for(Button bb : buttons){
        bb.setText(String.valueOf(a));
    }
}

This code will not assign a different letter to every button, but assign the same letter to all buttons.
Instead do this:

// omit unnecessary answer.shuffle() (`answer` will be shuffled anyway afterwards)

String allowed = "abcdefghijklmnopqrstuvwxy"; // add all allowed characters here

for (int i = 0; i < answer.size(); i++)
    buttons.get(i).setText("" + answer.get(i));

Random r = new Random();
for (int j = answer.size(); i < buttons.size(); j++)
    buttons.get(j).setText("" + allowed.charAt(r.nextInt(0, allowed.length())); // get a random character from `allowed`

Collection.shuffle(buttons); // shuffle buttons, so that they are in random order

In case you don't want characters to occur more than once you can you remove them from allowed after setting them as a button text.

edited Aug 1, 2014 at 17:02

answered Aug 1, 2014 at 16:21

i_turo

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3 Comments

user3439600 Over a year ago

They wont have the same size, each quiz question will have 20 buttons and the answer array will fill however many buttons and then the remaining buttons will be filled with other random characters, then the user has to try find the correct letters from the 20 buttons, guess the emoji, logo quiz etc has this feature if you have played any of them

i_turo Over a year ago

Ok, the code I have given will assign the answer letters to the first i buttons in the list.

user3439600 Over a year ago

Yeah i just tested it works good thank you for the help, would there be a way where i could fill the remaining buttons with other random letters and have the buttons scramble up so the first x buttons arent always the correct answer

Joaquim Ley · Accepted Answer · 2014-08-01 17:57:53Z

0

Well you could do the following:

Button btn;
for(int i = 0; i < answer.size(); i++){
   btn = buttons.get(Math.random() * (buttons.size()+1))
   if(btn.getText == null){
        btn.setText(String.valueOf(answer.get(i)));
   }
}

Then fill the remaining with random letters:

char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

// char[] alphabet = [a-z] May also work ;)

for(Button b: buttons){
    if(b.getText == null){
        b.setText(String.valueOf(answer.get(Math.random() * (alphabet.size()+1)));
    }
}

Assuming this works, this should put a "answer" letter in a random button, then fills the other buttons with other letters from a-z.

P.S: This assumes that the buttons text is "null" by default, you could/should change this

edited Aug 1, 2014 at 17:57

answered Aug 1, 2014 at 16:54

Joaquim Ley

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1 Comment

user3439600 Over a year ago

Doesnt return anything now, i had to cast the buttons.get(Math.random(); to an int but buttons are blank

Youcef LAIDANI · Accepted Answer · 2016-08-13 07:49:11Z

0

String[] Herifler={"q","ü","e","r","t","y","u","i","o","p","ö","ğ","a","s","d","F","G","H","J","K","L","ı","ə","Z","X","C","V","B","N","M","ç","ş"};

for(in i=0;i<30;i++) {
   buttons.get(i).setText(Herifler[i]);
}

Collections.shuffle(buttons);

edited Aug 13, 2016 at 7:49

Youcef LAIDANI

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answered Aug 13, 2016 at 7:19

Perviz

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